[PATCH] ext3: Wrong return value for EXT3_IOC_GROUP_ADD

This patch corrects the return value for the EXT3_IOC_GROUP_ADD in case it
fails due to the presence of multiple resizers at the filesystem.

The problem is a little bit more serious than a wrong return value in this
case, since the clause err=0 in the exit_journal path will lead to a call
to update_backups which in turns causes a NULL pointer dereference.
Signed-off-by: NGlauber de Oliveira Costa <glommer@br.ibm.com>
Cc: "Stephen C. Tweedie" <sct@redhat.com>
Cc: Andreas Dilger <adilger@clusterfs.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

fs/ext3/resize.c

@@ -767,6 +767,7 @@ int ext3_group_add(struct super_block *sb, struct ext3_new_group_data *input)
 	if (input->group != EXT3_SB(sb)->s_groups_count) {
 		ext3_warning(sb, __FUNCTION__,
 			     "multiple resizers run on filesystem!\n");
+		err = -EBUSY;
 		goto exit_journal;
 	}